[v2,4/5] x86: remove X86_FEATURE_XENPV usage in setup_cpu_entry_area()

Commit Message

Jürgen Groß Nov. 4, 2022, 7:27 a.m. UTC

Testing of X86_FEATURE_XENPV in setup_cpu_entry_area() can be removed,
as this code path is 32-bit only, and Xen PV guests are not supporting
32-bit mode.

Signed-off-by: Juergen Gross <[e-mail]>
---
V2:
- new patch
---
 arch/x86/mm/cpu_entry_area.c | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

Comments

Dave Hansen Nov. 4, 2022, 3:04 p.m. UTC | #1

On 11/4/22 00:27, Juergen Gross wrote:
> Testing of X86_FEATURE_XENPV in setup_cpu_entry_area() can be removed,
> as this code path is 32-bit only, and Xen PV guests are not supporting
> 32-bit mode.

Acked-by: Dave Hansen <[e-mail]>

Patch

diff --git a/arch/x86/mm/cpu_entry_area.c b/arch/x86/mm/cpu_entry_area.c
index 6c2f1b76a0b6..42cd96e7d733 100644
--- a/arch/x86/mm/cpu_entry_area.c
+++ b/arch/x86/mm/cpu_entry_area.c
@@ -138,17 +138,13 @@  static void __init setup_cpu_entry_area(unsigned int cpu)
 	pgprot_t tss_prot = PAGE_KERNEL_RO;
 #else
 	/*
-	 * On native 32-bit systems, the GDT cannot be read-only because
+	 * On 32-bit systems, the GDT cannot be read-only because
 	 * our double fault handler uses a task gate, and entering through
 	 * a task gate needs to change an available TSS to busy.  If the
 	 * GDT is read-only, that will triple fault.  The TSS cannot be
 	 * read-only because the CPU writes to it on task switches.
-	 *
-	 * On Xen PV, the GDT must be read-only because the hypervisor
-	 * requires it.
 	 */
-	pgprot_t gdt_prot = boot_cpu_has(X86_FEATURE_XENPV) ?
-		PAGE_KERNEL_RO : PAGE_KERNEL;
+	pgprot_t gdt_prot = PAGE_KERNEL;
 	pgprot_t tss_prot = PAGE_KERNEL;
 #endif